This invention relates generally to an adjuster for changing the position of a vehicular headlamp component for purposes of properly aiming the beam of the headlamp. A typical headlamp adjuster is disclosed in Ryder et al U.S. Pat. No . 4,674,018.
Many headlamp adjusters, such as that of the Ryder et al patent, utilize a pair of coacting bevel gears, one of which is adapted to be turned manually by an actuating rod and the other of which acts through a link to effect adjustment of the headlamp component. The gears are either die cast or are injection molded.
A less expensive headlamp adjuster uses a single and lower cost gear which is stamped from sheet metal. Adjustment is effected by inserting the tip of a Phillips screwdriver or similar tool between adjacent teeth of the gear and by turning the tool to cause rotation of the gear and adjustment of the headlamp component.
The need for using a screwdriver or other loose tool to directly rotate the stamped gear presents certain problems in that it may not be readily apparent to a mechanic as to how or by what means the gear is to be adjusted. Also, it may be difficult to gain access to the gear with a screwdriver and to prevent wobbling of the screwdriver while the screwdriver and the gear are being turned. In certain cases, it is desirable for the adjuster to be tamper-resistant (i.e., not capable of being adjusted by the vehicle owner) and this objective cannot be attained if the gear may be rotated by a commonly available screwdriver.